1. Field
This invention relates generally to fluid flow within the body of non-inflatable resting devices, and more particularly, to temperature control systems for non-inflatable resting devices such as cushion mattresses and seating devices.
2. Prior Art
People spend several hours of each day sitting or laying down on a surface, including a bed (e.g., mattress, mattress pad, etc.) or a seat (e.g., office chair, sofa, seating pad, seating cushion, etc.) Since it is often desirable to manage and control the temperature of the surface that contacts the person (e.g., to remove the heat trapped in the contact area), several existing solutions attempt to cool or heat the contact surface or the person to improve personal comfort.
For example, sofas and other pieces of furniture incorporate electrical and mechanical equipment inside the furniture and below the surface to be heated or cooled. Similarly, thermal blankets and mattress pads incorporate electrical heating elements to heat the contact surface. In addition to increasing the cost and complexity of the mattress or seat, these systems also increase the risks of hazardous conditions such as fire and electric shock.
Other prior art solutions for heating and cooling of non-inflatable resting devices include the use of cushioned mattresses, pads, and seats with a plurality of hoses through which a conditioned fluid (i.e. water, air) is circulated under a relative thick cushion layer. The contact surface of the resting device is required to provide the users with sufficient comfort and to have thermal conductivity to allow adequate heating or cooling of the users resting on these devices. However, an acceptable trade-off between the mattress comfortability and the energy efficiency of the heating and/or cooling system has proven to be a difficult goal to obtain. Among others, the main drawbacks of these solutions are one or more of the following, 1) the conditioned fluid must be pressurized through the use of motor driven compressors because of the requirement of the conditioned fluid to support the users' weight, making these solutions less energy efficient and more expensive due to the use of special sealed-tight hoses and connections, 2) the contact surface is made relatively thick due to the comfort level requirement, which in turn, adversely affects the thermal conductivity between the user and the conditioned fluid, 3) typically, the materials from which the contact surface is made of do not satisfactorily comply with the required thermal conductivity and mechanical strength, 4) the above performance deficiencies of the system imply that if air is used as the conditioned fluid, it needs to be blown onto the users through a multiplicity of holes located in the contact surface, and as a consequence, the system cannot be configured to work in a closed loop, and finally 5) when the heating and cooling system is configured as a closed loop, a more thermally efficient conditioned fluid is usually used, i.e., water. The mentioned drawbacks can be found on today's most popular heating and cooling mattress and pads such as the “ChilliPad”, “ChilliBed” and “CoolorHeat”.
Consequently, there still is a market need for a non-inflatable resting device which can provides the users with a low-cost efficient heating and cooling while maintaining high comfort level.